guarantee

1 guarantee /ˌgerənˈtiː/ noun
plural guarantees
1 guarantee
/ˌgerənˈtiː/
noun
plural guarantees
Britannica Dictionary definition of GUARANTEE
[count]
1 
: a usually written promise: such as
a  : a promise that the quality of something (such as a product that is being sold) will be as good as expected
b  : a promise that something is true or real
2 
: a promise that something will happen or be done
3 
: a thing that makes something sure to happen or exist — often used in negative constructions
4 
: something valuable that the owner will allow to be taken if a promise is not kept or a loan is not paid back
2 guarantee /ˌgerənˈtiː/ verb
guarantees; guaranteed; guaranteeing
2 guarantee
/ˌgerənˈtiː/
verb
guarantees; guaranteed; guaranteeing
Britannica Dictionary definition of GUARANTEE
[+ object]
1 
a  : to make a usually written promise that whatever you are selling, doing, etc., is what you say it is
b  : to promise to pay for (something) if another person fails to pay for it
2 
a  : to say (something) with great confidence
b  : to make (something) certain
c  : to say that (something) will certainly happen